Introduction to Android

Android introduction

• Mobile operating system based on Linux kernel
• User Interface for touch screens
• Used on over 80% of all smartphones
• Powers devices such as watches, TVs, and cars
• Over 2 Million Android apps in the Google Play store
• Highly customizable for devices / by vendors
• Open-source.

Android Devices

User interaction

• Touch gestures: swiping, tapping, pinching
• Virtual keyboard: for characters, numbers, and emoji
• External Devices: Support for Bluetooth, USB controllers, and peripherals
• Sensors: call receive by putting on-ear, playing games by moving mobile, etc.

Apps Examples

Android Architecture

• System and user apps -
• Android OS API in the Java framework
• Expose native APIs; run apps -
• Expose device hardware capabilities -
• Linux Kernel -
  
  

System and user apps

• System apps have no special status like that you must use it in your app.
• System apps provide key capabilities to app developers
• Example:    Your app can use a system app to deliver an SMS message.

Java API framework

• The entire feature-set of the Android OS is available to you through APIs that are written in the Java language.
• View class hierarchy to create UI screens
• Notification manager
• Activity manager for life cycles and navigation
• Content providers to access data from other apps

Android Runtime

• Each app runs in its own process with its own instance of the Android Runtime.

C/C++ libraries

• Core C/C++ Libraries give access to core native Android systemcomponents and services.

Hardware Abstraction Layer

• HAL stands for Hardware Abstraction Layer.
• Standard interfaces that expose device hardware capabilities as libraries
• Examples: Camera, Bluetooth module, etc.

Linux Kernel

• The Linux kernel is an operating system (OS) kernel defined as Unix-like in nature.
• Threading and low-level memory management
• Security features
• Drivers

History of Android

• Initially, Andy Rubin founded Android Incorporation in Palo Alto, California, the United States in October 2003.
• On 17th August 2005, Google acquired Android Incorporation.
• The key employees of Android Incorporation other than Andy Rubin are Rich Miner, Chris White, and Nick Sears.
• Developed and Managed by the OHA.